Public-source research has gaps. Search systems fail, communities restrict access, pages move, and some vendors publish less than others. A fair method has to show those limits without quietly turning every gap into a penalty.
Unavailable is not zero.
If PepGrades cannot measure a component reliably, that component is removed from the observed-weight calculation. The grade is marked Limited so the missing coverage remains visible.
Negative evidence requires an actual record.
A support failure, fulfillment problem, or misleading claim should affect a grade only when an admitted source supports that conclusion under the rubric. “We did not find it” is not the same claim.
Held and rejected records stay out.
A record can be held when an identity, source, or parsing issue is unresolved. It can be rejected when it fails a required admission rule. Neither contributes to the score unless a later versioned review changes its status.
Limited grades are still useful when read carefully.
A Limited B says the observed portions met the current threshold and some material information was unavailable. It does not say the unseen portion was good, bad, or complete. Readers can open the evidence view to see exactly what was and was not measured.
The label protects both readers and vendors.
Readers see the uncertainty before relying on a shortlist. Vendors are not punished for information PepGrades could not collect. That balance is central to a best-effort comparison service.